On Mon, Nov 22, 2021 at 03:22:11PM +0400, Roman Bogorodskiy wrote:
Martin Kletzander wrote:On Sun, Nov 21, 2021 at 07:58:55PM +0400, Roman Bogorodskiy wrote: >Recently, FreeBSD has got sched_get/setaffinity(3) implementations and >the sched.h header as well [1]. To make these routines visible, >users have to define _WITH_CPU_SET_T. > >This breaks current detection. Specifically, meson sees the >sched_getaffinity() symbol and defines WITH_SCHED_GETAFFINITY. This >define unlocks Linux implementation of virProcessSetAffinity() and other >functions, which fails to build on FreeBSD because cpu_set_t is not >visible as _WITH_CPU_SET_T is not defined. > >For now, change detection to the following: > > - Instead of checking sched_getaffinity(), check if 'cpu_set_t' is > available through sched.h > - Explicitly check the sched.h header instead of assuming its presence > if WITH_SCHED_SETSCHEDULER is defined > Makes sense, although even the sched_getaffinity() is guarded by the new _WITH_CPU_SET_T so there should be no error with the current code, am INope, as I tried to explain in the commit message, the current code is not working properly as it's using cc.has_function() for 'sched_getaffinity' and this check passes because it's checking the specified function in the standard library, so it works regardless of _WITH_CPU_SET_T. And as it finds the sched_getaffinity(), the build still fails because we don't set _WITH_CPU_SET_T.
Looking at the patches you linked to it seems like sched_getaffinity() is hidden under #ifdef _WITH_CPU_SET_T, which made me think that cc.has_function() should not find it. Anyway the code is fine as it is, I was just wondering. Reviewed-by: Martin Kletzander <mkletzan@xxxxxxxxxx>
right? And if I understand correctly we cannot use the FreeBSD implementation as is because they do not have all the CPU_* macros we need, right?Frankly speaking, I haven't yet tested this implementation. Currently, virprocess.c is using the original FreeBSD interface: cpuset_(get|set)affinity. Generally, it would be a good thing to use the same implementation for both Linux and FreeBSD, however, this Linux-compatible interface in FreeBSD is not yet available in any FreeBSD release, so we'll have to keep the old code for some time anyway, and also I need to test if it actually works for us and figure out how to better detect and pass this _WITH_CPU_SET_T with meson.
Maybe one day =)
>1: >https://cgit.freebsd.org/src/commit/?id=43736b71dd051212d5c55be9fa21c45993017fbb >https://cgit.freebsd.org/src/commit/?id=160b4b922b6021848b6b48afc894d16b879b7af2 >https://cgit.freebsd.org/src/commit/?id=90fa9705d5cd29cf11c5dc7319299788dec2546a > >Signed-off-by: Roman Bogorodskiy <bogorodskiy@xxxxxxxxx> >--- > meson.build | 4 +++- > src/util/virprocess.c | 8 ++++---- > 2 files changed, 7 insertions(+), 5 deletions(-) > >diff --git a/meson.build b/meson.build >index 9022bcfdc9..e4f36e8574 100644 >--- a/meson.build >+++ b/meson.build >@@ -553,7 +553,6 @@ functions = [ > 'posix_fallocate', > 'posix_memalign', > 'prlimit', >- 'sched_getaffinity', > 'sched_setscheduler', > 'setgroups', > 'setns', >@@ -602,6 +601,7 @@ headers = [ > 'net/if.h', > 'pty.h', > 'pwd.h', >+ 'sched.h', > 'sys/auxv.h', > 'sys/ioctl.h', > 'sys/mount.h', >@@ -671,6 +671,8 @@ symbols = [ > > # Check for BSD approach for setting MAC addr > [ 'net/if_dl.h', 'link_addr', '#include <sys/types.h>\n#include <sys/socket.h>' ], >+ >+ [ 'sched.h', 'cpu_set_t' ], > ] > > if host_machine.system() == 'linux' >diff --git a/src/util/virprocess.c b/src/util/virprocess.c >index 6de3f36f52..81de90200e 100644 >--- a/src/util/virprocess.c >+++ b/src/util/virprocess.c >@@ -35,7 +35,7 @@ > # include <sys/time.h> > # include <sys/resource.h> > #endif >-#if WITH_SCHED_SETSCHEDULER >+#if WITH_SCHED_H > # include <sched.h> > #endif > >@@ -480,7 +480,7 @@ int virProcessKillPainfully(pid_t pid, bool force) > return virProcessKillPainfullyDelay(pid, force, 0, false); > } > >-#if WITH_SCHED_GETAFFINITY >+#if WITH_DECL_CPU_SET_T > > int virProcessSetAffinity(pid_t pid, virBitmap *map, bool quiet) > { >@@ -626,7 +626,7 @@ virProcessGetAffinity(pid_t pid) > return ret; > } > >-#else /* WITH_SCHED_GETAFFINITY */ >+#else /* WITH_DECL_CPU_SET_T */ > > int virProcessSetAffinity(pid_t pid G_GNUC_UNUSED, > virBitmap *map G_GNUC_UNUSED, >@@ -646,7 +646,7 @@ virProcessGetAffinity(pid_t pid G_GNUC_UNUSED) > _("Process CPU affinity is not supported on this platform")); > return NULL; > } >-#endif /* WITH_SCHED_GETAFFINITY */ >+#endif /* WITH_DECL_CPU_SET_T */ > > > int virProcessGetPids(pid_t pid, size_t *npids, pid_t **pids) >-- >2.33.1 >Roman Bogorodskiy
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